Hold down system with distributed loading for building walls

ABSTRACT

A hold down system for a building wall comprises a first rigid member and a second rigid member, the second rigid member being vertically spaced apart from the first rigid member, the first rigid member is supported on a horizontal member of a stud wall, the first and second rigid members including first and second openings, respectively; a tie-rod with a lower end portion for being anchored to an anchorage, the tie-rod extending transversely through the first and second openings, the tie-rod dividing the first and second rigid members into a first lateral section on one side of the tie-rod and a second lateral section on a diametrically opposite side of the tie-rod; first support and second support disposed between the first and second rigid members, the first support being disposed in the first lateral section, the second support being disposed in the second lateral section, the tie-rod extending through the first and second rigid members outside of the first support or the second support; and a nut threaded to the tie-rod, the nut exerting pressure on the second rigid member to place the tie rod under tension loading, the tension loading is transferred by the second rigid member to the first and second supports to subject the first and second supports to compression loading, thereby causing the first rigid member to press on the horizontal member of the stud wall via the first and second lateral sections of the first rigid member, thus distributing the compression loading.

RELATED APPLICATION

This is a continuation application of nonprovisional application Ser.No. 16/932,921, filed Jul. 20, 2020, which is a continuation applicationnonprovisional application Ser. No. 16/432,745, filed Jun. 5, 2019,which is a continuation application of nonprovisional application Ser.No. 15/265,613, filed Sep. 14, 2016, which is nonprovisional applicationof provisional application Ser. No. 62/219,005, filed Sep. 15, 2015, allof which are hereby incorporated by reference.

FIELD OF THE INVENTION

The present invention is generally directed to a tension hold downsystem used in walls in light frame construction to resist uplift and tocompensate for wood shrinkage in wood frame construction and compressionloading.

SUMMARY OF THE INVENTION

The present invention provides a hold down system for a building wall,comprising a first rigid member and a second rigid member, the secondrigid member being vertically spaced apart from the first rigid member,the first rigid member is supported on a horizontal member of a studwall, the first and second rigid members including first and secondopenings, respectively; a tie-rod with a lower end portion for beinganchored to an anchorage, the tie-rod extending transversely through thefirst and second openings, the tie-rod dividing the first and secondrigid members into a first lateral section on one side of the tie-rodand a second lateral section on a diametrically opposite side of thetie-rod; first support and second support disposed between the first andsecond rigid members, the first support being disposed in the firstlateral section, the second support being disposed in the second lateralsection, the tie-rod extending through the first and second rigidmembers outside of the first support or the second support; and a nutthreaded to the tie-rod, the nut exerting pressure on the second rigidmember to place the tie rod under tension loading, the tension loadingis transferred by the second rigid member to the first and secondsupports to subject the first and second supports to compressionloading, thereby causing the first rigid member to press on thehorizontal member of the stud wall via the first and second lateralsections of the first rigid member, thus distributing the compressionloading.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a building wall using a hold down systemembodying the present invention.

FIG. 2 is an enlarged perspective view of an anchor assembly in FIG. 1 .

FIG. 3 is a perspective view of a slack absorber assembly of the holddown system in FIG. 1 .

FIG. 4 is a cross-sectional view along a longitudinal axis of one of theexpansion devices shown in FIG. 3 .

FIG. 5 is perspective view of a retainer ring shown in FIG. 4 .

FIG. 6 is a cross-sectional of the washers shown in FIG. 3 .

FIG. 7 is a perspective view of a building wall reinforced by a holddown system embodying the present invention.

FIG. 8 is a perspective view of a slack absorber assembly of the holddown system of FIG. 7 .

FIG. 9 is a cross-sectional view of the slack absorber assembly of FIG.8 .

FIG. 10 is a perspective view of a slack absorber assembly of the holddown system of FIG. 7 .

FIGS. 11-13 are alternative embodiments of the hold down system shown inFIG. 7 .

FIG. 14 is a perspective view of a cross-member used in the system shownin FIG. 13 .

FIG. 15 is a cross-sectional view along line 15-15 in FIG. 14 .

FIG. 16 is a perspective view of a building wall reinforced by a holddown system embodying the present invention.

FIG. 17 a perspective view of a slack absorber assembly in the hold downsystem of FIG. 16 .

FIG. 18 is an alternative location of the slack absorber assembly shownin FIG. 17 .

FIG. 19 is a perspective view of a building wall using a hold downsystem embodying the present invention.

FIG. 20 is a perspective view of a portion of the hold down system ofFIG. 19 .

FIG. 21 is a perspective view of a slack absorber assembly in the holddown system shown in FIG. 19 .

FIG. 22 is a cross-section view of the slack absorber assembly of FIG.21 .

FIG. 23 is a perspective view of a building wall using a hold downsystem embodying the present invention.

FIG. 24 is perspective view of a slack absorber assembly in the holddown system in FIG. 23 .

FIGS. 25 and 26 are a perspective view of a bracket in the slackabsorber assembly in the hold down system in FIG. 24 .

FIG. 27 is a top view of the bracket shown in FIGS. 25-26 .

FIGS. 28 and 29 are perspective views of a slack absorber assembly usedin a hold down system in any of the building walls shown above.

FIG. 30 is a perspective view of the washers used in the slack absorberassembly shown in FIG. 28 .

FIG. 31 is a bottom view of FIG. 30 .

FIG. 32 is a cross-sectional view of FIG. 30 .

FIGS. 33-35 are alternative embodiments of the washers shown in FIG. 30.

FIG. 36 is a perspective view of a slack absorber assembly used in ahold down system in any of the building walls shown above.

FIG. 37 is a cross-sectional view of the slack absorber assembly shownin FIG. 36 .

FIG. 38 is a perspective view of a slack absorber assembly used in ahold down system in any of the building walls shown above.

FIG. 39 is a perspective view of a slack absorber assembly used in ahold down system in any of the building walls shown above.

FIG. 40 is a cross-sectional view of the slack absorber assembly shownin FIG. 39 .

FIG. 41 is a perspective view of a slack absorber assembly used in ahold down system in any of the building walls shown above.

FIG. 42 is a cross-sectional view of the slack absorber assembly shownin FIG. 41 .

FIG. 43 is an assembly view of the slack absorber assembly shown in FIG.41 .

FIG. 44 is a perspective view of a slack absorber assembly used in ahold down system in any of the building walls shown above.

FIG. 45 is an assembly view of the slack absorber assembly shown in FIG.44 .

FIG. 46 is a cross-sectional view of the slack absorber assembly shownin FIG. 45 .

FIG. 47 is a perspective view of a slack absorber assembly used in ahold down system in any of the building walls shown above.

FIG. 48 is a cross-sectional view of the slack absorber assembly shownin FIG. 47 .

FIG. 49 is a side elevational view of a slack absorber assembly used ina hold down system in any of the building walls shown above.

FIG. 50 is a cross-sectional view of the slack absorber assembly shownin FIG. 49 .

FIG. 51 a perspective view of a slack absorber assembly used in a holddown system in any of the building walls shown above.

FIG. 52 is cross-sectional view of a split nut assembly shown in FIG. 51.

FIG. 53 is a top perspective view of the split nut assembly shown inFIG. 52 with the cover removed.

FIG. 54 is perspective view of a slack absorber assembly used in a holddown system in any of the building walls shown above.

FIG. 55 is an illustration of various combinations of the slack absorberassemblies disclosed herein.

FIG. 56 is cross-sectional view of a slack absorber assembly shown inFIG. 10 using a split nut assembly.

FIG. 57 is an assembly view of the split nut assembly shown in FIG. 56 .

FIG. 58 is a cross-sectional view of a slack absorber assembly embodyingthe present invention.

FIG. 59 is a perspective view of a slack absorber assembly embodying thepresent invention.

DETAILED DESCRIPTION OF THE INVENTION

A two-story building wall 2 using a hold down system 4 embodying thepresent invention is disclosed in FIG. 1 . The building wall 2 includesa base plate 6 supported by a concrete foundation 8, a plurality ofstuds 10 attached to the base plate 6, a double top plate 12 attached tothe studs 10, a plurality of floor joists (not shown, but see FIGS. 16and 17 ) supported on the double top plate 12, a subfloor 14 supportedon the floor joists, a bottom plate 16 supported on the subfloor 14, aplurality of studs 18 attached to the bottom plate 16, a double topplate 20 attached to the studs 18 and wall sheathing 22 attached to thestuds 10 and 22, the bottom plates 6 and 16, and the top plates 12 and20.

The hold down system 4 includes a tie rod 24 attached at one end to ananchor assembly 26 embedded in the concrete foundation 8. The other endof the tie rod 24 is attached to a slack absorber assembly 28 supportedby the top plate 20. The tie rod 24 is disposed within the wall 2,extending through openings in the base plates 6 and 16 and the topplates 12 and 20. The tie rod 24 may made of multiple sections joinedtogether into one with couplers 30.

Referring to FIG. 2 , the anchor assembly 26 includes an anchor support32, an anchor rod 34 attached to the anchor support 32 and an anchorbody 36 in the form of a hex nut threaded to the anchor rod 34. Theanchor rod 34 extends outside the foundation 8 through the base plate 6and connects to the tie rod 24 by means of the coupler 30. The coupler30 is threadedly attached to the anchor rod 34 and the tie rod 24.

The support 32 is described in U.S. Pat. No. 8,943,777, hereinincorporated by reference. Other standard supports may also be used.

The anchor body 36 may be of any shape that is suitable for embedment inconcrete and able to resist the uplift and shear loads of the buildingwall 2 during a storm, hurricane or earthquake. Other examples of theanchor body 36 are described in U.S. Pat. Nos. 8,943,777 and 9,097,001,hereby incorporated by reference.

Referring to FIG. 3 , the slack absorber assembly 28 includes a bottomrigid member 38 supported by the top plate 20, a left side expansiondevice 40, a center expansion device 42, a right side expansion device44, a top rigid member 46, a male washer 48, a female washer 50 and anut 52. The nut 52 is threaded to an end portion 54 of the tie rod 24 tokeep the expansion devices 40, 42 and 44 between the rigid members 38and 46. Each of the devices 40, 42 and 44 includes a spring 56 undercompression to tend to urge the top rigid member 46 away from the bottomrigid member 38, thereby to take up any slack that may later develop inthe tie rod 24 due to later shrinkage of the wall 2 due to settling,drying, etc. The springs 56 advantageously keep the tie rod 24 undertension. Removable clips 58 are used to keep the springs 56 fromexpanding during installation and are removed after installation of thedevices 40, 42 and 44 to activate the springs 56. The devices 40, 42 and44 are described in U.S. Pat. No. 7,762,030, hereby incorporated byreference.

The expansion devices 40, 42 and 44 provide support to the top rigidmember 46 and transfer the load to the bottom rigid member 38. The loadfrom the nut 52 as it applies tension load on the tie rod 24 isadvantageously distributed to the expansion devices 40, 42 and 44 andthence to the bottom rigid member 38. The expansion devices 40 and 44advantageously carry load offset from the tie rod 24, therebydistributing the load over a larger area. The load is distributed overthree expansion devices, thereby allowing each of the expansion devices40, 42 and 44 to be of smaller sizes that will fit in the limited spaceinside a wall than if a single expansion device were used.

Referring to FIG. 4 , the expansion device 40 is shown in cross-section,which also applies to the other expansion devices 42 and 44.Accordingly, only the expansion device 40 will be described.

The expansion device 40 includes an inner cylindrical member 60, whichis disposed within and slidable in an upward direction relative to anouter cylindrical member 62 under the action of the spring 56. The innercylindrical member 60 includes an axial opening 61. The inner andcylindrical members 60 and 62 are lockable relative to one another in adownward direction of the inner cylindrical member 60 to prevent thespring 58 from compressing to its prior position after the spring 58 hasexpanded to take up the slack in the tie-rod 24.

A retainer ring 64 is attached to an upper portion of the innercylindrical member 60 to keep the spring 58 wound around the outercylindrical member 62 at one end. The spring 58 is wound around anannular recess 66 around the outer cylindrical member 62 and an annularshoulder 68 at one end of the recess 66 keeps the spring 56 in place.The spring 58 is preferably helical. The removable clip 58advantageously prevents movement between the inner cylindrical member 60and the outer cylindrical member 62 during installation of the expansiondevice 40.

The retainer ring 64 includes flexible fingers 70 that are received inan annular recess 72 at the upper end portion of the inner cylindricalmember 60.

The inner cylindrical member 60 and the outer cylindrical member 62 haveopposing cylindrical walls 74 and 76, respectively, with correspondingreceiving volumes 78 and 80, respectively. A resilient member 82 isdisposed between the opposing cylindrical walls 74 and 76 and is biasedto occupy one of the receiving volumes 80. The receiving volumes 78 and80 are configured in cross-section such that when the inner cylindricalmember 60 is moved upwardly, the resilient member 82 is shifted into andfully received in one of the receiving volumes 78. The receiving volumes78 and 80 are further configured in cross-section such that when theinner cylindrical member 60 is subjected to a downward force, theresilient member 82 is only partially received within one of thereceiving volumes 80 to preclude movement of the inner cylindricalmember 60. The resilient member 82 is preferably a split ring.

The retainer ring 64 is preferably made of plastic with the fingers 70disposed inwardly and distributed around the opening 84. When installingthe retainer ring 64 to the inner cylindrical member 60, the retainerring 64 is pushed downwardly at the upper end of the inner cylindricalmember 60. The fingers 70 will flex and bend back into respectiverecesses 86 as the retainer ring 64 travels downwardly and then springback and engage the annular recess 72 when they get past the upper edge88 of the inner cylindrical member 60.

Referring to FIG. 6 , the male washer 48 includes a spherical convex topsurface 90 that mates with a bottom spherical concave surface 92 of thefemale washer 50. The washer 50 has an opening 94 configured for thediameter of the tie rod 24. The washer 48 has an opening 96 that islarger than the opening 94 to allow the washer 50 to move to one side orthe other side when the tie rod 24 is not installed perfectly vertical.The mating surfaces 90 and 92 advantageously remain in contact as thetop rigid member 46 rises unevenly to the left or to the right due to anuneven expansion of one of the expansion devices 40 and 44. The washers48 and 50 advantageously remain flat with the top rigid member 46 andthe nut 52 even when the tie rod 24 is not perfectly vertical orperpendicular with the top plates 20, and hence the bottom rigid member38 and the top rigid member 46. The bottom rigid member 38 and the toprigid member 46 also have oversize openings (through which the tie rod24 extends) similar to the opening 96 to accommodate the tie rod 24 notbeing perfectly vertical.

The opening 94 of the washer 50 may be threaded to mate with the threadon the tie rod 24 to advantageously provide the function of the nut 52so that the nut 52 can be eliminated to reduce the number of components,thereby saving cost and simplifying inventory. The washer 50 may beprovided with hexagonal flat surfaces in the manner of a standard nutfor use with a wrench or other standard tightening tool.

The bottom rigid member 38 and the top rigid member 46 are preferablyflat and planar and made of metal. The bottom rigid member 38 and thetop rigid member 46 may also be made of hollow metal, such as shown inFIGS. 14 and 39 . It should be understood that the top rigid member 46does not have to be a separate unit but may be built into the expansiondevices 40 and 44. Similarly, the bottom rigid member 38 may be part ofthe wall structure that provides the function of a bearing surface sothat it does not have to be provided separately, such as a tall woodblock as shown in FIG. 11 or a metal cross member as shown in FIGS. 12and 13 . It should be understood that the bottom rigid member 38 and thetop rigid member 46 are intended to mean any structure that provides abearing surface, whether separate or integrated with the expansiondevices.

Referring to FIG. 7 , a three-story building wall 98 is disclosed. Thewall 98 is similar to the wall 2 of FIG. 1 , but with the addition of athird story. A bottom plate 100 is disposed on a subfloor 102. Doubletop plates 104 are secured to the top ends of studs 106. Roof truss 108is supported on top of the double top plates 104.

A hold down system 110 is used to reinforce the building wall 98 againstuplift and shear forces. The system 110 includes the anchor assembly 26;the tie rod 24 connected to the anchor assembly 26; a slack absorberassembly 112 connected to the tie rod 24 to take up any slack that maydevelop later in the tie rod 24; a tie rod 114 connected to the tie rod24 through a coupler 116; a slack absorber assembly 118 connected to thetie 114 to take up any slack that may develop later in the tie rod 114;a tie rod 120 connected to the tie rod 114 with a coupler 122; and theslack absorber assembly 28.

Referring to FIG. 8 , the slack absorber assembly 112 is preferablydisposed on a bearing plate 124, which is supported by the bottom plate16. The slack absorber assembly 112 includes a left side expansiondevice 126, a right side expansion device 128, a bottom rigid member130, a top rigid member 132, threaded rods 134 that extend throughopenings 136 in the top rigid member 132 and threadedly attached tothreaded openings 137 in the bottom rigid member 130. The threaded rods134 are secured to the top rigid member 132 with nuts 138. The slackabsorber assembly 112 uses the male washer 48 and the female washer 50in the same manner as the slack absorber assembly 44. The nut 52attaches the slack absorber assembly 112 to the tie rod 24.

The tie rod 114 is smaller in diameter than the tie rod 24 due to thedecreased load above the slack absorber assembly 112. The smaller sizetie rod 114 advantageously provides for a cost savings. The coupler 116includes a larger threaded bore at one end for threaded attachment tothe tie rod 24 and a smaller threaded bore at the other end for threadedattachment to the tie rod 114. The coupler 116 is described inapplication Ser. No. 13/424,082, hereby incorporated by reference.

Because the center expansion device 42 is not used, the axial opening 61through the inner cylindrical member 60 does not have to be sized toaccommodate the diameter of the tie rod 24, advantageously providing theflexibility of reducing the overall diameter of the expansion devices tofit within the wall cavity. The overall diameter of the expansion device40 or 42 is advantageously independent of the diameter of the tie rod24, since the expansion device 40 or 42 does not surround the tie rod 24(i.e., the tie rod 24 does not pass through the expansion device 40 or42). For example, the diameter of the axial opening 61 of the innercylindrical member 60 can be smaller than the diameter of the tie rod24, or the axial opening 61 does not have to be provided so that theinner cylindrical member 60 can be made solid. The outside diameter ofthe inner cylindrical member 60 or the diameter of the axial opening ofthe outer cylindrical member 62 can even be smaller than the diameter ofthe tie rod 24. Further, the size of the rods 134 is also irrelevant ofthe size of the tie rod 24 or 114.

Referring to FIG. 9 , the expansion devices 126 and 128 are similar toany one of the expansion devices 40, 42 and 44 and work in the same way.The expansion devices 126 and 128 are described in U.S. Pat. No.7,762,030, herein incorporated by reference. After installation, thenuts 138 are removed to allow the top rigid member 132 to move upwardlyunder the action of the springs 56 when a slack develops in the tie rod24. The openings 136 are large enough to allow relative motion betweenthe rod 134 and the top rigid member 132. The removable clips 58 shownin FIG. 3 are not used, since the threaded rods 134 and the nuts 134provide the same function of holding the compressed springs 56 in placeprior to installation. The retainer rings 140 are respectively attachedto the inner cylindrical member 60. When the springs 56 expand due toslack in the tie rod 24, inner cylindrical member 60 moves upwardlyunder the action of the spring 56 while the outer cylindrical members 62are pressed by the spring 56 against the bottom rigid member 130.

The expansion devices 126 and 128 advantageously carry load offset fromthe tie rod 24, thereby distributing the load over a larger area. Theload is distributed over two expansion devices, thereby allowing each ofthe expansion devices 126 and 128 to be of smaller sizes that will fitin the limited space inside a wall than if a single expansion devicewere used.

Referring to FIG. 10 , the slack absorber assembly 118 includes the leftexpansion device 40 and the right expansion device 44. The slackabsorber assembly 118 is similar to the slack absorber assembly 28,except that the center expansion device 42 is not used. The removableclips 58 are removed after installation of the slack absorber assembly118 to allow the springs 56 to expand to take up any slack in the tierod 114. The tie rod 120 is smaller in diameter than the tie rod 114 dueto the smaller load above the slack absorber assembly 118. The coupler122 has a smaller threaded bore at one end for attachment to the tie rod120 and a larger threaded bore at the other end for threaded attachmentto the tie rod 114. The opening 142 in the bottom rigid member 38 isadvantageously oversized or elongated in the lengthwise direction of thebottom rigid member 38 to allow the tie rod 114 to be off the verticalto the left or to the right to accommodate a less perfect installation.Because the center expansion device 42 is not used, the axial opening 61through the inner cylindrical member 60 does not have to be sized toaccommodate the diameter of the tie rod 114, advantageously providingthe flexibility of reducing the overall diameter of the expansiondevices to fit within the wall cavity.

Referring to FIG. 11 , the building wall 98 is shown with a modifiedhold down system 114. The slack absorber assembly 28 disposed on thedouble top plate 104 shown in FIG. 7 has been moved to a positionbetween the bottom plate 100 and the top double plate 104. Reinforcementor jack studs 146 are attached to the studs 106 with nails or screws.The reinforcement studs 146 have bottom ends 148 engaging the bottomplate 100 and top ends 150 supporting a horizontal cross member 152. Thecross member 152 is advantageously made of a block of wood which istaller than its width. The slack absorber assembly 28 is supported bythe cross member 152.

Referring to FIG. 12 , the wooden cross member 152 may be replaced witha solid metal cross member 154.

Referring to FIG. 13 , the wooden cross member 152 may be replaced witha structural hollow metal cross member 156, as described in U.S. Pat.No. 9,097,000, incorporated herein by reference. The cross member 156includes a top wall 158 and a parallel bottom wall 160 connectedtogether with outside vertical walls 162 and inside vertical walls 164.Opening 166 in the top wall 158 and opening 168 in the bottom wall 160allow the tie rod 120 to extend through the cross-member 156. Thevertical walls 162 and 164 join with the top wall 158 and the bottomwall 160 with radius surfaces 170.

Referring to FIG. 16 , the wall 98 is shown with floor joists 172disposed between the subfloor 14 and the double top plate 12. Floorjoists 174 are also shown disposed between the subfloor 102 and thedouble top plate 20. A ring joist 176 is disposed between the subfloor14 and the double top plate 12. Another ring joist 178 is disposedbetween the subfloor 102 and the double top plate 20.

Referring to FIG. 17 , blockings 180 are disposed between the subfloor14 and the double top plate 12. The blockings 180 advantageously provideadditional support to the bottom plate 16 on which the slack absorberassembly 112 is disposed. The load from the slack absorber assembly 112is advantageously transferred through the blockings 180 to the studs 10below.

Referring to FIG. 18 , the slack absorber assembly 118 is disposed onthe double top plate 20. Blockings 182 are provided on each side of theslack absorber assembly 118. The blockings 182 are disposed between thesubfloor 102 and double top plate 20. The location of the slack absorberassembly 118 on the double plate 20 is an alternative location to thebottom plate 100.

Referring to FIG. 19 , the building wall 98 is reinforced with a holddown system 184, which includes a slack absorber assembly 186 disposedon the bottom plate 16. The slack absorber assembly 186 advantageouslytakes up slack from the tie rod 24 and the tie rods 114 and 120. An endportion of the tie rod 20 is tied to the double top plate 104 with abearing plate 188 and a nut 190, as shown in FIG. 20 .

Referring to FIGS. 21 and 22 , the slack absorber assembly 186 issimilar to the slack absorber assembly 112, shown in FIG. 9 , exceptthat the bottom rigid member 130 and the threaded rods 134 have beenextended and threadedly attached to respective threaded bores 192 in thebearing plate 124. The nuts 138 are screwed upwardly after installationa sufficient distance above the top rigid member 132 so as not tointerfere with upward movement of the top rigid member 132 as theexpansion devices 126 and 128 expand upwardly to take up any slack inthe tie rod 24.

The upper ends 194 of the threaded rods 134 are fixed to opposite endsof a member 196 through openings 198 and nuts 200. An expansion device202 identical to the expansion device 40 shown in FIG. 4 is attached toone end of the tie rod 114 that extends through an opening 204 of themember 196. The expansion device 202 advantageously takes up any slackthat may develop in the tie rod 114. A nut 206 secures the expansiondevice 202 to the member 196.

Referring to FIG. 23 , the building wall 98 is reinforced with a holddown system 206, which includes the anchor assembly 26, the tie rod 24and the slack absorber assembly 112, as shown in FIG. 7 ; a tie rod 208connected to the tie rod 24, a slack absorber assembly 210 with tie rods212 secured to a bracket 214 wrapped around the roof truss 108.

The slack absorber assembly 210 is the same as the slack absorberassembly 186, except that the threaded rods 134 are replaced with thetie rods 212 and the member 196 and expansion device 206 are not used.

Referring to FIG. 24 , the tie rods 212 are threaded to threaded bores192 (see FIG. 22 ) in the bearing plate 124. The tie rods 212 extendthrough openings in the double top plate 104 and are secured to thebracket 214 with nuts 216. The roof truss 108 is disposed transverselyto the double top plate 104 and includes an inclined member 216 and ahorizontal member 218. The roof truss 108 is of standard design.

Referring to FIGS. 25, 26 and 27 , the bracket 214 includes a U-shapedportion 220 and side flange portions 222. The U-shaped portion 220 isconfigured to fit over the inclined member 216. The flange portions 222each includes an elongated or slotted opening 224 to allow the tie rods212 to extend through the respective openings 224 at an angle withrespect to flange portions 222. The openings 224 are disposed on raisedarched portions 226 to advantageously allow the nuts 216 to be tightenedsufficiently when the nuts 216 are an angle with respect to the flanges222.

The U-shaped portion 220 includes a preferably planar or flat side wallportions 228 that are parallel to each other and a planar base wallportion 230 perpendicular to the side wall portions 228. The U-shapedportion 220 is configured to fit over and to the sides of the inclinedmember 216. The flange portions are preferably perpendicular to the sideportions 228 and parallel to the base portion 230. The bracket 214 ispreferably made from sheet metal.

Referring to FIGS. 28 and 29 , a slack absorber assembly 231 isdisclosed. The slack absorber assembly 231 is similar to the slackabsorber assembly 28 shown in FIG. 3 , except that the center expansiondevice 42 is not used. All other parts are designated with the samereference numerals. The slack absorber assembly 231 is advantageouslyused where the expected load is less than the expected load for theslack absorber assembly 28 such that the center expansion device 42 isnot used. Because the center expansion device 42 is not used, the axialopening 61 through the inner cylindrical member 60 does not have to besized to accommodate the diameter of the tie rod 234, advantageouslyproviding the flexibility of reducing the overall diameter of theexpansion devices to fit within the wall cavity. Openings 232 in thebottom rigid member 38 and the top rigid member 46 are oversized withrespect to the diameter of the tie rod 234 to allow the tie rod 234 tobe off the vertical (due to less than perfect vertical installation)when extending through the openings 232.

Referring to FIGS. 30, 31 and 32 , the top rigid member 46 shown in FIG.28 may be replaced with a top bearing 236 and the male washer 48 withmale washer 238. The top rigid member 236 has an elongated opening 240,which receives a cylindrical extension portion 242 of the male washer238. The male washer 238 has an annular flange 244 that sits on a topsurface 246 of the top rigid member 236. A gap 248 on each side of theextension portion 242 allows the extension portion 242 to move in eitherdirection to advantageously accommodate the tie rod 234 that may be afew degrees off from the vertical. The elongated opening 240 also allowsthe top rigid member 236 to be off the horizontal due to unevenexpansion of the expansion devices 42 and 44 while maintaining maximumsurface contact between the washers 50 and 238 and top rigid member 236.An opening 250 through the male washer 238 is oversized with respect tothe diameter of the tie rod to allow the tie rod within the opening tobe off from the vertical by a few degrees. The opening of the washer 50may be threaded to mate with the thread of the tie rod 234 toadvantageously eliminate the use of the nut 52, thereby reducing thenumber of components to save cost and simplify inventory. The washer 50may be provided with hexagonal flat surfaces in the manner of a standardnut for use with a wrench or other standard tightening tool.

Referring to FIGS. 33 and 34 , the top rigid member 46 shown in FIG. 28may be replaced with a top rigid member 252 and a centering washer 254.The top rigid member 252 has a concave surface 256 around the peripheryof an opening 258. The centering washer 254 has a corresponding convexsurface 260 around the periphery of an opening 262. The surfaces 256 and260 are preferably spherical to allow the centering washer 254 to swivelover the opening 258. The opening 258 is oversized with respect to thediameter of the tie rod to allow the tie rod within the opening to beoff from the vertical by a few degrees.

Referring to FIG. 35 , the top rigid member 252 may be provided with aconvex surface 264 around the periphery of the opening 258 instead ofthe concave surface 260 shown in FIG. 34 . The convex surface 264 risesabove the top surface 266 of the top rigid member 252. The centeringwasher 254 may be provided with a concave surface 268 instead of theconvex surface 260 shown in FIG. 34 . The surfaces 264 and 268 arepreferably spherical surfaces to advantageously allow swiveling motionof the centering washer 254 around the opening 258.

The opening 262 of the washer 254 may be threaded to mate with thethread of the tie rod 234 to advantageously eliminate the use of the nut52, thereby reducing the number of components to save cost and simplifyinventory. The washer 254 may be provided with hexagonal flat surfacesin the manner of a standard nut for use with a wrench or other standardtightening tool.

Referring to FIG. 36 , a slack absorber assembly 270 is disclosed thatis similar to the slack absorber assembly 128 shown in FIGS. 8 and 9 ,except that the bottom rigid member 130 is replaced with a hollow rigidmember 272. The hollow rigid member 272 is structurally the same as thecross-member 156 shown in FIG. 14 so that the same reference numeralsare used to designate the various portions of the hollow rigid member272.

Referring to FIG. 37 , the threaded rods 134 are threaded in threadedopenings 274. The nuts 134 keep the slack absorber assembly 270 inactiveuntil after installation at which time the nuts 134 are removed.

Referring to FIG. 38 , a slack absorber assembly 276 is disclosed. Theslack absorber assembly 276 is similar to the slack absorber assembly270 shown in FIG. 36 , except that the top rigid member 132 is replacedwith a hollow rigid member 278, which is structurally the same as thehollow rigid member 272 except for size. Accordingly, the hollow rigidmember 278 will not be described further.

Referring to FIG. 39 , a slack absorber assembly 278 is disclosed. Theslack absorber assembly 278 is similar to the slack absorber assembly118 shown in FIG. 10 , except that the top rigid member 46 is replacedwith a hollow rigid member 280, which is tubular and rectangular incross-section. The hollow rigid member 280 has a top wall 282, a bottomwall 284 and side walls 286. Referring to FIG. 40 , the depth of thehollow rigid member 280 is about the same width as the expansion devices40 and 44. The hollow rigid member 280 is advantageously narrow so thatthe force from the male washer 48 is transferred laterally to the sidewalls 286 in the shortest possible distance.

Referring to FIGS. 41, 42 and 43 , a slack absorber assembly 288 isdisclosed. The slack absorber assembly 288 includes left and rightexpansion devices 290 disposed on either side of a tie rod 292. Eachexpansion device 290 works by relative rotational movement between anouter cylindrical member 294 and an inner cylindrical member 296 due toan unwinding of a torsion spring 298. The spring 298 under compressionis effective to cause relative rotational motion between the innercylindrical member 296 and the outer cylindrical member 294. The innercylindrical member 296 has outer thread 300 that engages with an innerthread 302 of the outer cylindrical member 294. The inner cylindricalmember 296 has a flange portion 304 with a radial hole 306 for securingone end of the torsion spring 298. Similarly, the outer cylindricalmember 294 has a radial hole 308 for securing the opposite end of thetorsion spring 298.

A removable clip 310 is used to prevent relative movement between theinner cylindrical member 296 and the outer cylindrical member 294 duringinstallation. Leg portions 312 are received within circumferentialgroove 314 at the bottom portion of the inner cylindrical member 296 andextend past the bottom edge 316 of the outer cylindrical member 294,thus preventing relative movement between the inner cylindrical member296 and the outer cylindrical member 294.

Bolts 318 attach the expansion devices 290 to the top rigid member plate46. Each of the bolt 318 is threaded to the respective inner thread 320of each inner cylindrical member 296, thereby fixing the innercylindrical member 296 to the top rigid member 46.

Once the slack absorber assembly 288 is installed in place at a locationwithin the building wall 98, the clips 310 are removed. The outercylindrical member 294 is then free to rotate in an unscrewing mannerfrom the inner cylindrical member 296 due to the action of the torsionspring 298 when a slack develops in the tie rod 292. The unscrewingaction of the outer cylindrical member 294 extends the length of theexpansion device 290, thereby absorbing any slack that develops in thetie rod 292. The inner cylindrical member 296 stays fixed to the toprigid member 46 while the outer cylindrical member 294 is rotatable inthe unscrewing direction when a slack develops in the tie rod 292.

Since the expansion devices 290 are disposed outside the tie rod 292(i.e., the tie rod does not enter and extend through the expansiondevices), the respective diameters of the components of the expansiondevices 290 can be sized without regard to and is independent of thediameter of the tie rod 292, and vice versa. For example, the diameterof the tie rod 292 is shown as being larger than the diameter of theinner thread 320 of each inner cylindrical member 296. In this case, thediameter of the tie rod 292 can be chosen to be large enough to act as acompression member to take up a compression load. Further, the size ofthe bolts 318 is also irrelevant of the size of the tie rod 292.

The expansion devices 290 advantageously carry load offset from the tierod 292, thereby distributing the load over a larger area. The load isdistributed over two expansion devices, thereby allowing each of theexpansion devices 290 to be of smaller sizes that will fit in thelimited space inside a wall than if a single expansion device were used.

Referring to FIG. 44 , a slack absorber assembly 322 with an expansiondevices 324 and 326, both of which are identical. The expansion device324 has started to expand due to a slack in the tie rod 328 while theexpansion device 326 has remained inactive because the clip 310, due toan omission by the installer, has not been removed. In this situation,the expansion devices 324 and 326 are configured so that both devicesadvantageously continue to squarely bear on the top rigid member 330.The expansion devices 324 and 326 are similar to the expansion device 40shown in FIG. 4 but with modifications.

Referring to FIGS. 45 and 46 , each of the expansion devices includes aninner cylindrical member 332 disposed within the outer cylindricalmember 68. A resilient member or split ring 333 is received in one ofthe circumferential grooves 335 in the inner cylindrical member 332 andcorresponding circumferential inside grooves 337 in the outercylindrical member 62. The spring 56 is retained around the outercylindrical member 68 between the shoulder 68 and the retainer ring 64,which is attached to the inner cylindrical member 332, as alreadydiscussed in reference to FIG. 4 . The top edge surface 334 of the innercylindrical member 332 is convex, preferably spherical, that mates witha corresponding bottom concave surface 336 of a washer 338. The washer338 in combination with the surface 334 allows the washer 338 to swivel,thereby making maximum surface contact with the top rigid member 330,even when the top rigid member 330 is not level.

Threaded rods 340 are threaded to threaded openings 342 in the bottomrigid member 344. The threaded rods 340 are slidably received within theinner cylindrical members 332 to guide the inner cylindrical members 332in their upward movement as slack develops in the tie rod 328.

A washer 348 includes an upper concave surface 350, preferablyspherical. Another washer 352 with a convex surface 354, preferablyspherical, mates with the washer 348 to allow the washer 352 to swivelwith respect to the washer 348 when the top rigid member 330 is notlevel. This allows the nut 356 to make maximum surface contact with thewasher 352 even when the top rigid member 330 is not level. The openingof the washer 352 may be threaded to mate with the thread of the tie rod328 to advantageously eliminate the use of the nut 356, thereby reducingthe number of components to save cost and simplify inventory. The washer356 may be provided with hexagonal flat surfaces in the manner of astandard nut for use with a wrench or other standard tightening tool.The uneven expansion of the expansion devices may also be due to somefactors, such as manufacturing tolerances, etc. The rounded edge 334 andthe mating washer 338 advantageously allow for maximum surface contactwith the top rigid member 364 even when the expansion devices do notexpand at the same rate.

It should be understood that the washers 350 and 352 are interchangeablewith the two washer system shown in FIGS. 6 and 30-32 and themodifications to the top rigid member shown in FIGS. 33-35 .

Referring to FIG. 47 , a slack absorber assembly 358 is shown afterhaving expanded to take up a slack in the tie rod 360. The slackabsorber assembly 358 includes the expansion device 324 and the washers352 and 348 shown in FIGS. 44-46 . The threaded rod 340, which isthreaded to the threaded hole 342 in a bottom plate 362, slidably guidesthe inner cylindrical member 332 in its upward motion as driven by thespring 56 when a slack develops in the tie rod 360. The washer 338swivels with respect to the convex surface 334 to maintain maximumsurface contact with the top rigid member 364.

A support member 366 disposed on the other side of the tie rod 360provides support to the top rigid member 364 as the expansion device 324expands to take up the slack that develops in the tie rod 360. Thesupport member 366 includes a rounded upper edge surface 368 that mateswith a corresponding rounded groove 370 in the underside of the toprigid member 364. As one side of the top rigid member 364 above theexpansion device 324 moves upwardly, the opposite side supported by thesupport member 366 pivots about the surfaces 368 and 370. The bottomedge portion 372 is held in a groove 374 in the bottom rigid member 362.

In the arrangement of the slack absorber assembly 358, the expansiondevice 324 carries substantially half the load, the other half beingcarried by the support member 366. The washers 348 and 352advantageously provides maximum surface contact between the nut 356 andthe washer 352 and between the washer 348 and the top rigid member 364.The washer 338 swivels with respect to the convex surface 334 tomaintain maximum surface contact with the top rigid member 364.

Referring to FIGS. 49 and 50 , a slack absorber assembly 376 isdisclosed. The slack absorber assembly 376 uses the expansion device 40shown in FIG. 4 on either side of the tie rod 378. The expansion device290 shown in FIG. 41 is disposed such that the tie rod 378 extendsthrough it. The inner cylindrical member 296 (FIG. 43 ) is slidably andaxially movable relative to length of the tie rod 378 as the expansiondevice 290 expands to take up the slack in the tie rod 378. The washers48 and 50 shown in FIG. 6 are also used. In this configuration, thelooseness in the expansion devices 40 while in between locking positions(when the resilient member 82 is between two receiving volumes 80,referring to FIG. 4 , during the process of expanding) is advantageouslytaken up by the expansion device 290, which is always engaged, therebyreducing the inherent looseness in the system.

Referring to FIG. 51 , a slack absorber assembly 380 is disclosed. Theslack absorber assembly 380 includes expansion device 126, also shown inFIG. 8 . The expansion devices 126 are disposed between the bottom rigidmember 382 and the top rigid member 385 and on either side of the tierod 384. Threaded rods 386 are attached to the bottom rigid member 382and are slidably movable through the top rigid member 385 as theexpansion devices 126 expand to push the top rigid member 385 upwardlyto take up any slack that develops in the tie rod 384. Swivel washers 48and 50, also shown in FIG. 6 , provide maximum surface contact with thetop rigid member 385 and the nut 52 to account for uneven expansion ofthe expansion devices 126.

A split nut assembly 388 is disposed around the tie rod 384. The splitnut assembly 388 has a housing 390, which is operatively attached to thebottom rigid member 382 with standard means, such as with bolts 392. Acylindrical nut 394 split axially into equal segments 395, preferablyfour, is disposed within the housing 390 and threadedly engaged with thetie rod 384. A split ring 396 disposed within a circumferential groove398 biases the cylindrical nut 394 toward the tie rod 384. The bottomportion of the cylindrical nut 394 includes a bevel or ramp 400 thatcooperates with a corresponding circumferential ramp 402 around thebottom portion of the housing 390. A cover 404 is removably attached tothe housing 390 with screws 406. A gap 408 is provided between innervertical surface 410 of the wall 412 and the outer vertical surface 414of the cylindrical nut 394. A gap 415 is provided between the bottom ofthe cover 404 and the top of the split nut 394. The gap 408 allows thesegments of the cylindrical nut 394 to separate away from the tie rod384 and disengage when the cylindrical nut 394 hits and presses againstthe cover 404 after traversing the gap 415 as the tie rod 384 is pulledupwardly by the expansion devices 126 when a slack develops in the tierod 384. In the same manner, when the wall shrinks and settles, thebottom rigid member 382 moves with the wall, causing the cylindrical nut394 to press against the cover 404 and thereby separating from the tierod 384.

The overall diameter of the expansion device 126 is advantageouslyindependent of the diameter of the tie rod 384, since the expansiondevice 126 does not surround the tie rod 384 (i.e., the tie rod 384 doesnot pass through the expansion device 126). For example, referring toFIG. 4 , the diameter of the axial opening 61 of the inner cylindricalmember 60 can be smaller than the diameter of the tie rod 24, or theaxial opening 61 does not have to be provided so that the innercylindrical member 60 can be made solid. The outside diameter of theinner cylindrical member 60 or the diameter of the axial opening of theouter cylindrical member 62 can even be smaller than the diameter of thetie rod 24. Further, the size of the rods 386 are also irrelevant of thesize of the tie rod 384.

Referring to FIG. 54 , a slack absorber assembly 418 is disclosed. Theslack absorber assembly 418 includes split nut assemblies 420, 422 and424 disposed between a bottom rigid member 426 and a top rigid member428. The split nut assemblies 422 and 424 provide support between thebottom rigid member 426 and the top rigid member 428. The split nutassemblies 420-424 are structurally and functionally the same as thesplit nut assembly 388 shown in FIGS. 52 and 53 , including respectivecylindrical nuts 394. The split nut assembly 420 is attached to thebottom rigid member 426 with bolts 429 or other standard means. Thebottom rigid member 426 is attached with screws 431 or other standardmeans to the wall structure 427, such as the stud wall base plate. Thesplit nut assemblies 422 and 424 are attached to the 428 with bolts orother standard means. The split nut assemblies 422 and 424 are orientedinverted with respect to the split nut assembly 420. The split nutassemblies 422 and 424 are attached to the top rigid member 428 withbolts 433 or other standard means. Threaded rods 430 and the tie rod 432cooperate with the respective cylindrical nuts 394 in the same way asalready described with the split nut assembly 388 shown in FIGS. 52 and53 . The threaded rods 430 are attached to the bottom rigid member 426,such as by threading into respective threaded holes in the manner shownin FIG. 9 . The threaded rods 430 are slidably movable through the toprigid member 428 through respective openings in the manner shown in FIG.9 . A nut 434 attaches the top rigid member 428 to the tie rod 432 suchthat the top rigid member 428 remains stationary with respect to the tierod 432.

The tie rod 432 due to its relatively larger diameter (larger than whatis required for the load) acts as a post such that when the wall shrinksor settles, the slack absorber assembly 418 moves with the wall, sincethe bottom plate 426 is attached to the wall structure 427. The threadedrods 430 moves with the bottom plate 426, causing the respectivecylindrical nuts 394 in the split nut assemblies 422 and 424 to pressagainst the respective covers 404 and disengage from the respectivethreaded rods 430. When movement ceases, the respective split rings 396bias the segments 395 to engage the respective threaded rods 430 and thetie rod 432. When uplift occurs due to wind or other forces, therespective cylindrical nuts 394 will engage the respective threaded rods430 and the tie rod 432 from the cooperating actions of the respectiveramp surfaces 400 of the respective cylindrical nuts pressing againstthe corresponding respective ramp surfaces 402 of the respectivehousings.

Referring to FIG. 55 , devices A, B, C, D and E are disclosed in variousconfigurations between the bottom rigid member 436 and the top rigidmember 438. Devices A and B are the same type as the expansion device126 disclosed in FIG. 9 . Device C is the same type as the expansiondevice 290 without the bolt 318 as shown in FIG. 43 . Devices D and Eare split nut assemblies 388 of the type shown in 52 and 53.

Where there are three devices shown in a row, the middle device isdisposed in the center with the tie rod 440 extending through the middledevice. The tie rod 440 is able to move relative to the middle device.The threaded rods 442 are attached to the bottom rigid member 436 andprovide a guide for the upward movement of the left and right devices.

In the following discussion, the various configurations are labeled asB-B, A-B, A-C-A, A-B-A, B-E-B and D-E-D.

In the B-B configuration, the left device B is offset from the rightdevice B so that they do not lock at the same time. This effectivelyshortens the locking distance 446, which is the distance between thereceiving volumes 80, and therefore, reduces the looseness in thesystem. When one of the devices is locked, as shown for the rightdevice, the resilient member 82 of the other device will be between twoadjacent receiving volumes, as shown for the left device. Thiseffectively shortens the locking distance by about a half. The distance446 for the device B on the left is equal to the distance 446 on thedevice B on the right. The illustrated distance 446 is 0.0750 in. Forthe arrangement shown, there is locking every 0.0375 in. withoutshortening the distance 446 between the receiving volumes 80. Shorteningthe distance 446 is not preferable to avoid shearing of the receivingvolumes 80 during load conditions. The configuration advantageouslymakes system tighter to effectively withstand the load it is designedfor.

In the A-B configuration, the distance 448 in the device A betweenadjacent volumes 80 is longer than the distance 450 for the device B. Inthe illustrated example, the locking distance 448 of the device A is0.2000 in. versus the locking distance 450 of 0.0750 in. of the deviceB. This means that the device B will lock about two times before thedevice A locks. This ensures that there will be more chances that one ofthe devices will be locked at any time to hold the tie rod 384 tight tothe foundation against any uplift forces, thereby decreasing thelooseness in the system without decreasing the strength of thecomponents. The configuration advantageously makes system tighter toeffectively withstand the load it is designed for.

In the A-C-A configuration, the center device C is always engaged totake up the entire load when the devices A are between lockingpositions. The distances 452 are equal to each other, for example 0.2000in. The looseness of the relatively long distance 452 is advantageouslyabsorbed by the threads of the center device C. The configurationadvantageously makes system tighter to effectively withstand the load itis designed for.

In the A-B-A configuration, the locking distance 454 for the centerdevice B is shorter than the locking distance 456 for the devices A. Theconfiguration ensures that the center device B is locked more times thanthe outlying devices A. As an example, the distance 454 is 0.0750 in.while the distance 456 is 0.2000 in. This configuration advantageouslyreduces the looseness of the outlying devices A by having the centerdevice with shorter locking distance 454. The configurationadvantageously makes system tighter to effectively withstand the load itis designed for.

In the B-E-B configuration, the device E is attached to the bottom rigidmember 436. The tie rod 384 is relatively larger in diameter (largerthan what is required for the load) so that it acts as a post. When thewall shrinks and settles downwardly, the split nut opens up and movesdownwardly to engage the lower thread portion. The outlying devices Bwill expand to take up the slack between the nut 444 and the top rigidmember 438. The locking distance 458 for the devices B is illustrated at0.0750 in. while the thread pitch 460 for the screw threads is longer,illustrated at 0.1429 in. This will ensure that the devices B are lockedwhen the split nut is still open, thereby taking up the looseness in thesystem. The configuration advantageously makes system tighter toeffectively withstand the load it is designed for.

In the D-E-D configuration, as already described in connection with FIG.54 , the shorter thread pitch 462 for the devices D as compared to thethread pitch 464 of device E allows for tightness of the assembly incase the threads of the device E do not engage completely due to amovement of less than the thread pitch of the device E. The thread pitch462 is illustrated as 0.0769 in. while the thread pitch 464 is 0.1429in.

With the use of combination of expansion devices with different lockingdistances, looseness in the system is advantageously reduced to make thesystem tighter to effectively withstand the load it is designed for.

It should be understood that other combinations are also possible, suchas D-D, E-E, E-B and C-C. Further, any one of the devices A, B, C, D andE may be used in the configuration shown in FIG. 47 , in lieu of theexpansion device 324.

Referring to FIG. 56 , the standard nut 52 is replaced with a split nutassembly 466. The split nut assembly 466 is similar to the split nutassembly 388 shown in FIGS. 52 and 53 . A nut 468 split axially intofour segments 470 are disposed inside a housing 472. A cover 474 isscrewed to the housing 472. The cover 474 includes an inside conicalsurface 476 that cooperates with a circumferential flange 478 at theupper portion of the nut 468. A circumferential groove 480 is providedbetween the conical surface 476 and an inside conical surface 482 at theinside upper portion of the housing 472. The inside bottom portion ofthe housing 472 includes a conical surface 484 that cooperates withcorresponding conical surface 486 at the bottom portion of the nut 468.Resilient split rings 488 disposed in respective circumferential grooves489 hold the segments 470 of the nut 468 together. Space 490 between thenut 468 and the inside surface of the housing 472 allows the nut 468 toexpand and disengage from the thread of the tie rod 486.

In operation, when the split nut 468 is slid down the tie rod 492 untilit engages the washer 50. With the application of a downward force, theconical surface 476 causes the circumferential flange 478 to rise intothe groove 480, thereby forcing the opening of the nut 468. When adownward force is exerted on the tie rod 492, the nut 468 tightensaround the tie rod 492 from the action of the bottom conical surface 486against the housing conical surface 484.

It should be understood that the split nut assembly 468 may be used inany of the slack absorber assemblies disclosed herein in lieu of thenuts 52, 356 and 444.

Referring to FIG. 58 , a slack absorber assembly 493 is provided with atop rigid member 494 with a threaded opening 496 that mates with thethread on the tie rod 492. The threaded top rigid member 494advantageously eliminates the use of the standard nut 52. The slackabsorber assembly 493 is similar to the slack absorber assembly 231shown in FIG. 28 , except that the washers 48 and 50 and the nut 52(shown in FIG. 3 , for example) is not used. The tie rod 492 due to itsrelatively larger diameter (larger than what is required for the load)acts as a post such that when the wall shrinks or settles, the expansiondevices 40 and 44 expands downwardly to take up any gap that developsbetween the bottom rigid member 38 and the horizontal wall structure,such as the wall bottom plate 16 or 100, on which the bottom rigidmember 38 rests. The opening 232 is oversized to avoid interference withthe tie rod 492 during the downward expansion of the slack absorberassembly 493.

Referring to FIG. 59 , the slack absorber assembly 112 shown in FIG. 9is modified as slack absorber assembly 498 with elongated threaded rods500 and an extended bottom rigid member 502 that extends below thebottom ends of the studs 106. The placement of the bottom rigid member502 advantageously provides additional bearing surface on the wallbottom plate 100 and additional load bearing connections with the wall.In addition to the load imposed by the expansion devices 40 and 44, thestuds 106 provide additional load transfer to the wall.

The nuts 138 after installation of the slack absorber assembly 498 areunscrewed a distance from the top rigid member 46. This allows theexpansion devices 40 and 44 to expand only to the limit of the positionsof the nuts 138, as the top rigid member 46 moves upwardly along thethreaded rods 500. The nuts 500 disposed a distance from the top rigidmember 46 advantageously act as stops for the top rigid member 46 andthe expansion devices 40 and 44 such that the inner cylindrical member60 will not overshoot the outer cylindrical member 62 during expansion,thereby insuring that the inner cylindrical member 60 remains locked tothe outer cylindrical member 62 when a downward force is exerted by thetop rigid member 46 when the wall is subjected to lift or shear forcesduring a storm, earthquake, etc.

It should be understood that the various expansion devices describedherein are interchangeable with one another in any of the various slackabsorber assemblies disclosed herein. For example, the expansion device290 may be substituted for the expansion devices variously labeled as40, 42, 44, 126, 128, 324, and 326 or the split nuts variously labeledas 388, 422 and 424.

While this invention has been described as having preferred design, itis understood that it is capable of further modification, uses and/oradaptations following in general the principle of the invention andincluding such departures from the present disclosure as come withinknown or customary practice in the art to which the invention pertains,and as may be applied to the essential features set forth, and fallwithin the scope of the invention or the limits of the appended claims.

I claim:
 1. A hold down system for a building wall, comprising: a) afirst rigid member for being supported on a horizontal member of a studwall, the first rigid member including a first opening; b) a split nutdisposed on the first rigid member; c) a tie-rod with a lower endportion for being operably anchored to a foundation, the tie-rodextending transversely through the first opening and the split nut, thesplit nut engaging the tie-rod to resist tension load on the tie-rod; d)the split nut including a housing and nut segments disposed in thehousing; e) the nut segments being completely enclosed inside thehousing; and f) first and second vertical studs with respective bottomends bearing on the first rigid member.
 2. The hold down system as inclaim 1, wherein: a) the nut segments include a ramp surface; and b) thehousing includes an inside bottom surface with a ramp surfacecorresponding to the ramp surface of the nut segments.
 3. The hold downsystem as in claim 1, and further comprising: a) a second rigid membervertically spaced from the first rigid member, the second rigid memberincluding a second opening, the tie-rod extending through the secondopening and being fixedly attached to the second rigid member at alocation; b) the first rigid member and the second rigid memberincluding a first section laterally of the tie-rod and a second sectionlaterally on an opposite side of the tie-rod; and c) a first supportdisposed between the first section of the first rigid member and thefirst section of the second rigid member, the first support beingconfigured to maintain the location of the second rigid member to thetie-rod.
 4. The hold down system as in claim 3, wherein a nut bears ontop of the second rigid member.
 5. The hold down system as in claim 4,wherein a swivel washer is disposed between the nut and the second rigidmember.
 6. The hold down system as in claim 3, wherein the first supportincludes a first spring disposed around a first cylindrical body.
 7. Thehold down system as in claim 3, and further comprising a second supportdisposed between the second section of the first rigid member and thesecond section of the second rigid member, the second support beingconfigured to maintain the location of the second rigid member to thetie-rod.
 8. The hold down system as in claim 7, wherein the secondsupport includes a second spring disposed around a second cylindricalbody.
 9. The hold down system as in claim 7, wherein: a) the firstsupport and the second support include a first split nut and a secondsplit nut, respectively, attached to the second rigid member; b) a firstthreaded rod and a second threaded rod attached to the first rigidmember and extend through the second rigid member; c) the first splitnut and the second split nut disengage from the first threaded rod andthe second threaded rod when the first rigid member moves downwardlywith the horizontal member of the stud wall; and d) the first split nutand the second split nut engage the first threaded rod and the secondthreaded rod when the first rigid member moves upwardly with thehorizontal member of the stud wall.
 10. The hold down system as in claim3, wherein the first support includes a spring.
 11. A hold down systemfor a building wall, comprising: a) a rigid member for being supportedon a horizontal member of a stud wall, the rigid member including anopening; b) a split nut disposed on the rigid member; c) a tie-rod witha lower end portion for being operably anchored to a foundation, thetie-rod extending transversely through the opening and the split nut,the split nut engaging the tie-rod to resist tension load on thetie-rod; and d) first and second vertical studs with respective bottomends bearing on the rigid member.
 12. A hold down system for a buildingwall, comprising: a) a first rigid member for being supported on ahorizontal member of a stud wall, the first rigid member including afirst opening; b) a split nut disposed on the first rigid member; c) atie-rod with a lower end portion for being operably anchored to afoundation, the tie-rod extending transversely through the first openingand the split nut, the split nut engaging the tie-rod to resist tensionload on the tie-rod; d) a second rigid member vertically spaced from thefirst rigid member, the second rigid member including a second opening,the tie-rod extending through the second opening and being fixedlyattached to the second rigid member at a location; e) the first rigidmember and the second rigid member including a first section laterallyof the tie-rod and a second section laterally on an opposite side of thetie-rod; and f) a support disposed between the first section of thefirst rigid member and the first section of the second rigid member, thefirst support being configured to maintain the location of the secondrigid member to the tie-rod.
 13. The hold down system as in claim 11,wherein: a) the split nut includes a housing; b) the nut segmentsinclude a ramp surface; and c) the housing includes an inside bottomsurface with a ramp surface corresponding to the ramp surface of the nutsegments.